Speed control of landing gear wheels on aeroplanes



. 8, 1936. 2,063,032 SPEED CONTROL OF LANDING-GEAR WHEELS ON AEROPLANES c. D. FATOR 2 Sheets-Shet 1 Filed April 9, 1955 )NVENTOR I Gharles DJaior 2 HTTOIRN 2 Sheets-Sheet 2 C. D. FATOR Filed April 9, 1935 Dec. 8, 1936.

. INVENTOR 7 Charles D. IZzfion FTTORNEY Patented Dec. 8, 1936 PATENT" OFFICE SPEED CONTROL OF LANDING GEAR WHEELS ON AEROPLANES Charles'D. Fator, San Antonio, Tex. Application April 9, 1935, Serial No. 15,453

3 Claims.

This invention described herein may be manufactured and used byror for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to a new and useful improvement in aeroplanes, more particularly it is directed to the provision of means on an aeroplane for facilitating the landing thereof.

' One of the objects of the invention is to provide means on an aeroplane for causing the landing wheels thereof to rotate at substantially the same speed as that of the landing speed of the plane.

Another object of the invention is to provide means on an aeroplane .to lessen the chance of tilting or overturning thereof when landing, and to prolong the life of the tires provided on the Y landing wheels of the plane.

Other objects of the invention are to provide means of the character stated which are simple in construction and arrangement, strong, durable, eflicient, compact and conveniently operated, which may be readily installed in an aeroplane already'constructed as well as form com-.

ponent parts of a. new structure, and which is comparatively inexpensive to manufacture, install and maintain.

when an aeroplane is landing with the wheels stationary the sustaining effect of the wings of the plane plus the power necessary to start the wheels thereof rotating. causes the tires on the wheels to drag for some distance on contacting the ground whereby a terrific grinding away of the thread of the tires is efiected particularly when the plane is of the heavy transport type and further with the wheels of the plane stationary a condition is encountered whereby the plane ordinarily has aatendency to tilt or nose 'over which tendency is due in part to the inertia of the wheelscaused by the sudden acceleration.

It is therefore the aim and purpose of this invention to provide means for facilitating the landing of an aeroplane by lessening thechance of tilting or overturning thereof and to prolong the life of the tires on thelandln wheels of the plane. Y I

with .the above and other objects and advantages in view, the invention specifically consistsin features of. constructio arrangement'and operation of parts which will hereinafterappeer. For purposes of illustration the invention will be. described and claimed with reference to the aceompanyins drawings in which like members immaterial-mammalian:

- during the flight of the'plane.

mounted and (Granted under the act of March 3, amended April 30, 1928; 370 0.

Fig. 1 is a front elevation of an aeroplane having my invention applied thereto;

Fig. 2 is a side elevation of a speed control unit used in carrying out my invention;

Fig. 3 is a front view of a control panel for I the speed control unit;

Fig. 4 is a diagrammatic view of a closed fluid circulating system used in carrying out my invention; I

Fig. 5 is a horizontal sectional view of a gov- 10 ernor mechanism adapted to control a pumpunit shown in elevation; I

Fig. 6 is a horizontal sectional view of the pump unit; Y

Fig. 7 is a cross sectional view on line 1-1 of Fig 5;

Fig. 8 is a fragmentary vertical sectional view of a valve unit used in carrying out my invention and applied to the right hand side of the control unit, and -11 Fig. 9 is a side elevat'on of the landin wheels thereof taken 16 of the plane equipped with my improved means for causing rotation thereof when landing.

In the illustrated embodiment characterizing the invention l denotes an aeroplane provided 25 with a landing gear on which are revolubly' mounted landing wheels 2 including the usual heavy rubber tires 3. The wheels 2 are provided with a plurality of propelling vanes 4 on the sides thereof which vanes are spaced equally to so each other around the periphery of the wheels and so disposed that the air will impinge against the working surface thereof and cause the wheels to be rotated rapidly in a forward direction, as indicated by the arrow in Fig. 9 of the As the rotation of the landing wheels 2 is required and desired only while landing, each of the wheels 2 is covered by the pants 5 having a suction tube 8 provided'therein which leads into propelling ing of the aperture.

covereducables a which are connected by one end thereoftothe'shuttergateslandby their-other endtoonieendofarodllwhichisintumconnectedto a control unit indicated gen rally inFig.'2-of the drawings. v oted at I! ma projecting portion ll provided onaframe lionwhichthe'eontrolmnthis extends outwardly thrown an? by A and illustrated The lever II is pivdrawings. as

lever H at I: of a control 50 66 to'the members 31 and the other end thereof I on the upper and lower ends into a conduit 29 ing members 31 7 construction and pump units 4| and of the displacement pump units 33 and opening 16 provided in the frame l5 and through aguide slot l6 provided in one side of a panel l1 mounted on the control unit. A handle l8 having a plunger button I9 provided therein is fitted on the outer end of the lever II. The plunger button I9 is adaptedto contact with the outer end of a pin 26 which is mounted movably within a longitudinally extending slot 2| provided in. the lever H; The pin 26 is provided with a ratchet 22 on the inner end thereof which is adapted to engage in vided on the upper and lower ends respectively of the guide slot I6 of the panel I 1 when the lever II is in an operative or land position as illustrated for opening the gates 6, or in an inoperative or fly position for closing the same. The ratchet 22 is also adapted to engage ratchet teeth 25 provided along the inner surface of the guide slot l6 when the lever II is in partial inoperative position.- A compression spring 26 is provided in the handle l8 to detachably hold the ratchet 22 in the recesses 23 and 24 provided respectively of the slot l6 as well as the ratchet teeth 25 intermediate thereof. I

In order to control the speed of the wheels 2 for causing the same to rotate at substantially the landing speed of the plane, a closed fluid.

circulating system is provided which is diagrammatically illustrated in Fig. 4 of the drawings. Referring to Figs. 2 and 4 of the drawings, the fluid circulating system comprises a fluid reservoir 21 which is connected in the system by means of a conduit 28 which extends downwardly from the bottom of the reservoir and branches having a. refill cock 36 on the which provides means for keeping the system charged. The reservoir 21 is made of suitable flexible material to allow for expansion and contraction of the fluid in the whole system due totemperature changes. In order to draw the air from the system particu larly in the initial charging thereof with fluid, a bleed cock 3| is connected to the upper end of the reservoir 21 by means of a conduit 32. The conduit 28 leads into the outlet side of a pair of positive displacement pump units 33 and 34, the

operation of which will hereinafter be described; it also branches into conduits 35 and 36 which are provided with connecton the lower ends thereof which are fitted in apertures 36 provided in the bottom of the frame-i5. The members 31 provide means for connecting conduits 39 and 46 thereto, one end of said coriduits 39 and 46 being connected outer end thereof being connected to the inlet side of a pair of gear type displacement pump units 4| and 42 which are mounted on the axle assembly for the wheels 2 and in driving connection with the wheels by being geared to the left and right wheels respectively of the aeroplane. The pump units 4| and 42 as will hereinafter appear, provide a braking action on the wheels 2 for controlling the rotational speed thereof. The fluid in the system is conducted from the outlet side of the brake 42 to the inlet side of the fluid displacement pump units 33 and 34 by means of conduits 43 and 44 respectively, which connect with connecting members on the lower ends of conduits 43' and 44' of check valve 46 is provided in the system for each 34, and

a recess 23 and 24 pro and 44 serves to unseat either valve 31' provided which lead. into inlet side of thepump units 33 and 34. "A freely operating mono-directional type -frame ii of the control unit by a screw 46 or the like. The valves 46 "and .41 are operated by levers 56 and 6| respectively which are pivoted at 52 to diaphragms 63 which are made of suitable material such as metal and brased to 'the body portion 46, thereby serving as a positive fluid seal for the fluid passing through the valve body.

The passageway 64 provides means for connecting the exhaust side of the valves 46 and 41 to the conduit 26. The outer ends of the levers 56 and 5! threadably engage the upper screwthreaded end of a shaft 55 and are held in spaced relation to each other by springs 56 and adjusting nuts 51. The shaft 55 is pivoted at the lower end thereof to a link 56 which is in turn pivoted at 56 to a fluid valve control lever 66 which operates in a guide slot 6| provided in the panel I 1 to control the valves 46 and 41. The valves 46 and 41 are operated simultaneously by thevalve control lever 66 and in the present illustration the valve -46 is shown in a closed position as both valves 46 and 41 would be when the lever is in the land position as illustrated in Fig. 3 of the drawings. In this closed position the valves act as high pressure relief valves and any ex- .cess pressure built up'in either the conduits 43 46 and 41 I respectively to let the fluid escape back into the conduits as being in an open position as both valves would be with the fluid valve control lever 66 in a fly position and in this open position the valves 46 and 41 act as by-pass valves allowing full passage of the fluid for the conduits 43 and 44 to conduits 39 and 46 without anyundue'braking of the landing wheels if they are rotating.

The fluid displacement pump units 33 and 34 are formed into a single unit as illustrated in Figs. 5, 6 and 7 of the drawings and each comprises a pair of gears 62 and 63 which are enclosed within a housingv 64 having a cover 66 provided thereon which is held in place by means of screws 66. An outlet passageway 61 is provided in the housing 64 which leads from the delivery side of the pump 33 to the pressure or delivery side of the pump 34. The inlet side 66 of the displacement pump units 33 and 34 is connected to the outlet side of the brake pump units 4i and 42. pump units 33 and 34 are driven from and by ashaft 63 through a gear wheel 16 which is in mesh with a driving pinion 1| of a governor mechanism for controlling! the speed of the pump units and thus the amount of fluid displaced thereby, as illustrated inFig. 5 of the drawings. The driving pinion 1| is mounted on a shaft 12 which is driven by a suitable motor 13 which in the present instance is proposed to be started when the fluid valve control lever 66 is in the land position is in the fly position. The driving pinion 11 is partially enclosed within .a support 14 having anti-friction ball bearings 16 on which one 'end of the shaft 12 is adapted to be rotated. The governor mechanism includes a as and 40. The valve 41 is illustrated and stopped when the lever provided therein 70 v the shaft 1.2 and support I4 and at the other ends to which.

u suctiontubeiandilnpm mtbepfwem l .landing speed pointer check valves 48 .with little thereof to a braking wheel 18 movably mounted on the shaft 12. A compression spring 88 is provided on the shaft 12 for holding the braking wheel I8 in an outward position. The support 14 is provided with an outwardly projecting portion 8| on the lower end thereof containing an aper- I ture 82 in which a rod 83 is mounted for holding the brake wheel 18 in a predetermined position on the shaft and thereby causes the governor to operate at a particular speed for controlling the pumps 33 and 34. The outer end of the rod 83 is provided with a brake tact with the wheel I9 and the inner end thereof is pivoted to one end of a lever arm 85 which is in turn flxably secured to a shaft 88 which is pivotally secured by one end to the outer end of a screw threaded bolt 81. The bolt 81 is connected threadably in a recess 88 provided in the support 14 and has an adjusting nut 88 mounted on the inner end thereof for taking up wear of the brake shoe. In order to prevent the nut 88 from turning due to vibration or the like a lock spring 8|! is provided on the support 14. The shaft 88 which is fixably secured to the lever arm 85 and pivoted to the bolt 81 at one end extends out through an aperture 8| provided in the lower end of the frame l5 and panel I! and engages the lower end of a control pointer 82 which is flxably secured thereto by a screw 83 as illustrated in Figs. 2 and 3 of the drawings. A suitable index chart 84 including a color division 85 for indicating the normal landing speed of the plane-is provided on the upper end of the panel the pointer 82 is adapted to be set for various speeds of the plane. The pointer 82 is moved to the various points on the index I speed chart 84 by means of a finger grip Q8 having a pin 81 provided on the inner end thereof which is adapted to engage movably in suitable spaced openings 88 provided in the panel ll to hold the pointer 82 in a fixed position thereon. 88 which is secured to the panel A guide member |'I by screws I88 may be provided pointer 82.

In the operation of the invention assumin that a pilot is about to land the plane I, the

82isseton thespeedindex 84 to the desired speed at which the landin wheels 2 should frotate, which moves the ,rod 83 of the control mechanism'to a predetermined position and thus prevents the governor from driving the. pump units 33 and 34 more than desired by the brake wheel I8 contacting with the brake for guiding the shoe-on the-outer encrof therod. 'lhefluid controlvalve' lever 88 is then moved to the land podtion as indicated on Fig. 3 of the drawings, which serves'to close the valves 88 and 8| to make them act as high-pressure reiiefand check-valves. The

lever 88 may be so connected to the drive motor '13 to start the same, in whichcase upon starting the-motor I3 the displacement pump units 33 and 34-are driven at the proper speed-as set by the pointer 82 which controls the action (R the governor mechanism. Thepump units 33 and 34 immediately reach the desired speed and circulate the fluid in the system through the ornopower low. 'lheleverllisthenmovedtothelandposition therebyopeningtheshuttergatesCasillustrated inrigs.land3ofthedrawings,whichallowsa highvelocityairstreamtopassthroughthe shoe 84 adapted to con- 'valves 45 to close.

' rotational of the landing speed of the plane, said last menvanes 4 provided on the wheels 2 thereby cans through the check valves 45. The moment thebrake pump units 4| and 42 displace the same amount of fluid in the system as does the dis? placement pump units 33 and 34, any tendency to increase the displacement of the brake pump units 4| and 42 causes a pressure to be built up in the conduits 43 and 44, which causes the check Whenever the brake pump units 4| and 42 begin to displace more fluid than the pump units 33 and 34, the built up pressure in the conduits 43 and 44 causes a suitable and proportionate braking efiect to be applied to the wheels 2, thereby preventing the wheels froni rotating faster than the speed at which the pump units 4| and 42 will displace a volume of fluid equal to that being displaced by the pump units 33 and 34. Thus any excess power applied to the wheels 2 by the propelling vanes 4 is dissipated and the wheels are prevented from rotating in excess of the speed at which the pacemaker control pointer 82 is set. I

For taking off and taxying on the ground when no braking effect is desired on the wheels, the fluid valve lever 88 is moved to the fly position, which causes the valves 48 and 41 to act as bypass valves allowing the fluid in the system free passage through the conduits and 44 respectively.

'It will thus be seen that I have provided highly novel and efllcient means which are well adapted as and 4: and 4c for all the purposes indicated. Even thoughIhave Having described my invention, what liclaim' asnew and wish to secure by Letters Patent is:

1. In an aeroplane including a landing gear having landing wheels mounted revolubly thereon, means for rotating said landing wheels in a forward direction during the flight of the aeroplane, means for substantially synchronizing the speed of said landing wheels to that tioned means comprising a covering for said landing wheels. an exposure aperture provided in said covering, means operable for opening and closing said aperture, a closed fluid circulating system including a fluid displacement pump in driving connection with each of said wheels and providing a braking action thereon; a motor, fluid displacement pumps driven by said motor and adapted to control the braking action of said first men tioned pumps, conduits connecting said first men tioned pumps to said last mentioned pumps, a fluid circulated by saidpumns'. check and com bination by-pass' check and presume-relief valves in said conduits, said valves being responsive to thepressurewithinsaidsystemand mean for controlling the speed of said displacement pumps driven by said motor.

llnanaeroflaneincludingalandinggear on; means for rotating said landing wheels in a forward direction during the flight of the aeroplane, means for substantially synchronizing the rotational speed of said landing wheels to that of adapted to control the braking action 0! said first mentioned pumps, conduits connecting said first v mentioned pumps to said last mentioned pumps, a fluid circulated by said pum check and combination by-pass, check and pressure-relief valves in said conduits, said valves being responsive to the pressure within said system, and means for controlling the speed of said displacement pumps driven by said motor, means connected in. said conduits for taking up the expansion and contraction of the fluid in the system and means connected to said last mentioned means for keeping the system charged and drawing air therefrom.

3 In an aeroplane including a landing-\ gear having landing wheels mounted revolubly thereon, means for rotating said landing wheels in a forward direction during the flight of the aeroplane, means for said motor and adapted therein enclosing said landing whels,.

2,068,039 v having landing wheels mounted revolubly theremeans operable for partially exposing said landing wheels, a control unit, a panel including-guide slots and a speed index chart provided thereon, a control lever pivotably connected to said control unit and adapted to work in one 01' said slots for operating said exposure means, a closed fluid circulating system including a fluid 'displace-' ment pump in driving connection with each of said wheels and providing a braking action thereon; a motor, fluid displacement pumps driven by to control the braking action or said first mentioned pumps, conduits connecting said first mentioned pumps to said valves being responsive to the. pressure within said system, means for controlling the speed of said displacement pumps driven by said -motor including a pointer adapted to be moved to various points on said speed index chart, a fluidvalve lever adapted to work in the other of said slots in said panel for controlling the action of said combination by-pass check and pressure relief valves; means connected on said system for taking up the expansion and contraction of the fluid and means mounted in said panel and connected to said last mentioned means for draining air from the system and keeping said system 30 charged.

, CHARLES D. FATOR. 

